The present invention relates generally to conveyorized food cooking apparatus and, more particularly, to an apparatus for conveyorized toasting of breads and like food items, particularly sliced bread items such as sandwich buns.
The toasting of sliced breads and sandwich buns in the making of hamburgers and other sandwiches is a common practice not only to suit individual tastes and preferences but also to effectively carmelize and seal the faces of the bread to resist absorption of juices and condiments used in the sandwich. Many commercial establishments use bread toasters of the same basic type in widespread home use, comprising a housing with one or more upwardly facing slots for placing multiple slices of bread into a spring-loaded cage by which the bread slices may be lowered into a disposition within the housing between opposed facing heater elements for a predetermined period of time. While such toasters have proven reasonably effective to achieve the intended surface toasting of bread slices, such toasters suffer the significant disadvantages of being relatively slow, often taking in excess of one to one and one-half minutes to achieve the desired surface carmelization of the bread, and are also quite limited in capacity, which makes such equipment relatively undesirable for commercial use in high capacity food preparation establishments such as fast food restaurants. Also, such equipment typically cannot accommodate a variety of differing types and sizes of sliced breads and, in particular, often cannot accommodate hamburger and like sandwich buns or bagels.
Other commercial restaurants utilize a conventional commercial griddle of the type having a stationary base with a flat upwardly facing heated platen and a pivoted cover also comprising a heated platen. While the contact pressure exerted by the pivoted lid on bread slices may enable such griddles to achieve a toasting effect in a somewhat shorter period of time than the conventional toasters of the type described above, the contact pressure may negatively affect the appearance of a toasted bread slice or bun and, further, the capacity of such griddles is still limited by the surface area of the platens.
A conveyorized bread toasting apparatus is described in Miller U.S. Pat. No. 4,530,276, granted Jul. 23, 1985, entitled CONTACT TOASTER and a commercial version of such conveyorized toaster is believed to have achieved a reasonable degree of acceptance within the fast food industry. The conveyorized toaster of the Miller patent is designed particularly for toasting the two halves of hamburger and like sandwich buns and basically utilizes a heated platen centrally disposed within a housing between a pair of oppositely traveling conveyors by which the crown and heel portions of a sandwich bun may be conveyed along the opposite sides of the platen to achieve toasting. While such apparatus addresses the disadvantage of low capacity suffered by the more traditional toasters and griddles described above, the effective increase in capacity has proved to be less than optimal in actual practice because the apparatus still requires one to one and one-half minutes to achieve effective toasting. The Miller patent further teaches only the toasting of the open faces of a sandwich bun, i.e., the sliced surfaces, and thus utilizes the central platen as the sole means of toasting the two bun halves, without any toasting of the outward crown and heel sides thereof, which is believed to be considered by many persons within the restaurant industry and among the general public as an additional disadvantage.
The disadvantages of the conveyorized bread toasting apparatus of Miller U.S. Pat. No. 4,530,276, are overcome by an improved conveyorized bread toasting apparatus disclosed in Stuck U.S. Pat. No. 5,673,610. This bread toasting apparatus is also particularly designed for high speed, large capacity, commercial use. Like the Miller apparatus, this apparatus also provides a central heated platen with two bun transport conveyors traveling in spaced relation along opposite sides of the platen, but in contrast also provides a pair of auxiliary heating elements disposed outwardly of the respective food transport runs of the conveyors in facing relation to the opposite sides of the platen, whereby sandwich buns and like bread and food items are simultaneously toasted on opposites sides. Advantageously, this apparatus in practice has been successful in achieving more uniform toasting of a conventional hamburger bun than with the commercial version of the Miller apparatus in substantially shorter times, generally on the order of only about 20 seconds. To facilitate rapid transport of sandwich bun halves through the toasting apparatus, a sheet coated with polytetrafluoroethylene (e.g., TEFLON7 brand material) is affixed in surface abutment over both side faces of the central heated platen to promote easy sliding movement of the bun halves and to resist sticking. Disadvantageously, however, it has been found in practice that, at the substantially higher temperatures needed to promote such rapid toasting, e.g., with the central platen heated to a temperature on the order of 575.degree. Fahrenheit, the polytetrafluoroethylene sheeting tends to rapidly degrade from continuous direct exposure to such temperatures, with the useful life of such sheeting being on the order of only about two to three weeks before replacement becomes necessary.